import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        String str=sc.nextLine();
        StringBuilder stringBuilder=new StringBuilder(str);
        for(int i=str.length()-3;i>0;i-=3){
            stringBuilder.insert(i,",");
        }
        System.out.println(stringBuilder.toString());
    }
}